Third SLAM in as many months...can I break the cycle?

[Brittanibcroft]

As the title reads, we've been through the SLAM process once a month since opening in March. We are so ready to enjoy our pool and not spend so much time, energy, and frustration bringing it back to life. Obviously we are making some mistakes along the way and I'm really hoping to break the cycle this time, but need some help. Here's where we're at...

Started SLAM Tuesday 6/2 and just passed the OCLT last night, so I *think* we are in the clear right now.

Current levels are...

FC - 23
CYA - 70
ALK - 90
pH - Tested 8.2+ but it's not reliable during SLAM, correct? So this would be irrelevant right now?

A few questions...

1) Should I add a little stabilizer to keep my CYA from dropping below 70?
2) Add muriatic acid to bring down both Alkalinity and pH? pH should be re-testable once my FC is lowered to the ideal range of 4-6, correct?
3) Obviously there's got to be a reason why we keep ending up back with algae...any input would be appreciated so we can troubleshoot and prevent another repeat. I've wondered if we need to do any of the following: clean our sand filter (it's been 3-4 years, and we get a fair amount of sand out of one of our returns, if that matters), replace our salt cells (5 years old), deal with pool lights that don't work that could be harboring the enemy? Photos of lights attached. The deep end light looks very green

Thank you guys for any input or advice! Learning the hard way over here!

**About the photos: our pool is terribly stained...so you'll notice that really stands out in the photos. Heading over to Everything Else shortly to seek advice on that.

 

[kellyfair]

A few things... since you are having recurring problems, wait until you pass OCLT two or three nights before assuming SLAM is over.

Are you testing FC daily otherwise? Is the level being maintained by running the salt cell the way Pool Math instructs? Can you see tiny bubbles when it is on, and do you see any scaling on the cell?

CYA doesn’t drop unless water is replaced, so no need to add more. Don’t mess with PH either while your FC is so high - wait until it falls to below 10, after the SLAM.

Certainly scrub the light niches (another reason not to end SLAM yet.)

While there shouldn’t be a need to replace sand, you shouldn’t see a bunch coming in at the return, either. So opening it up, removing sand, and checking for broken laterals is a good idea.

 

[Brittanibcroft]

A few things... since you are having recurring problems, wait until you pass OCLT two or three nights before assuming SLAM is over.

Are you testing FC daily otherwise? Is the level being maintained by running the salt cell the way Pool Math instructs? Can you see tiny bubbles when it is on, and do you see any scaling on the cell?

CYA doesn’t drop unless water is replaced, so no need to add more. Don’t mess with PH either while your FC is so high - wait until it falls to below 10, after the SLAM.

Certainly scrub the light niches (another reason not to end SLAM yet.)

While there shouldn’t be a need to replace sand, you shouldn’t see a bunch coming in at the return, either. So opening it up, removing sand, and checking for broken laterals is a good idea.

Kelly, thank you so much for the input! I never thought to keep testing to pass the OCLT multiple nights in a row, so I'll be sure to continue testing for another night or two.

I have not been testing FC daily but knew as soon as we had this last bloom that I need to be. Shame on me. I was testing once or twice a week, and the last time it was quickly losing FC we couldn't find bleach in time to get it back up before it was long gone. If I finish this SLAM successfully, I will better be able to tell what my SWG is producing/where it's maintaining when I'm testing daily. I guess that would be the best way to determine if my cells are still good.

Yes to tiny bubbles, also yes to scaling, but not extreme. I admit I have not done the best job keeping the build up off, but we've also struggled to keep the salt level high enough the last few years too...finally got a legitimate salt test kit from the TF store...the strips from Amazon were all over the place.

Thank you for the other suggestions! Certainly adding them to our to-do list.